Greek parliament approved on Wednesday evening a draft bill to clear the way for privatizing public power corporation PPC-DEI, despite protests by workers and opposition parties.

The bill on the liberalization of the energy market passed with 51 votes in favor, 46 against and one deputy voting present.

A total of 98 lawmakers participated in the procedure during the parliament's summer session which consists of a third of the 300-member strong plenary.

The draft foresees the company's split into two entities and the sale of the smaller part which accounts to 30 percent of shares to private investors next year.

The two-partite conservative-led coalition government argues that PPC-DEI's partial privatization will help to strengthen the company to the benefit of Greek consumers.

The trade union of PPC-DEI workers GENOP-DEI with the backing of other labor unions and opposition parties has launched a mobilization against the step, claiming that the privatization will harm workers' rights and Greek taxpayers.

As legislators debated the draft on Wednesday evening, outside the parliament employees held a rally, vowing to continue their "struggle" despite the outcome.

PPC-DEI workers were forced back to work with a civil mobilization order during the weekend, after a court ruled that the rolling strikes they launched on June 1 caused short power cuts amidst the summer tourism season and were illegal.

Main opposition Radical Left SYRIZA party meanwhile leads efforts for the conduction of a referendum on the matter. The party is set to submit the proposal in parliament on Thursday.

Under Greek legislature, SYRIZA needs 120 votes to put the issue on the agenda in the first place and the parliament must approve the proposal by at least 180 votes in favor so that a referendum can be conducted.

According to political analysts in Athens, it seems unlikely at the moment that the proposal can garner 180 votes in the assembly.

In the meantime, SYRIZA leader Alexis Tsipras is expected to visit Greek President Karolos Papoulias and ask the latter not to ratify the bill until the proposal for a referendum is discussed.

Four years after the start of an acute debt crisis which brought Greece to the brink of bankruptcy, by implementing a harsh austerity and reform program in exchange of vital bailout aid by international lenders, Greece has achieved remarkable progress in fiscal consolidation, but still lags in reforms, according to officials and analysts.